Scientists discover how sleep boosts memory

A new study reveals the mechanism by which a good night’s sleep improves memory and learning.

Using advanced microscopy, scientists from the US and China have discovered the mechanisms of memory – that new connections between brain cells (synapses) form during sleep.

Although it is already known that sleep is important for helping to improve memory and learning, this new study – published in the journal, Science – highlights what actually happens inside the brain.

Researchers at New York University School of Medicine and Peking University Shenzhen Graduate School carried out the study by training mice to walk on top of a rotating rod.

After teaching them this new skill, the scientists used a microscope to look inside the brains of the mice to see what happened when the animals were either sleeping or sleep deprived.

The results showed that the mice that slept formed many more new connections between neurons – learning more than the mice that were having their sleep disrupted.

This brain activity of ‘replaying’ events from earlier in the day highlights how a deep or slow sleep is crucial for memory formation.

Prof Wen-Biao Gan, from New York University, said: “Finding out sleep promotes new connections between neurons is new, nobody knew this before.

“We thought sleep helped, but it could have been other causes, and we show it really helps to make connections and that in sleep the brain is not quiet, it is replaying what happened during the day and it seems quite important for making the connections.”

In another part of the study, scientists identified exactly how important sleep was for improving performance as well as memory.

Mice doing up to an hour of training followed by sleep were compared with mice who trained intensively for three hours but then sleep deprived.

The differences were again quite stark, with the sleepers performing better.

Prof Gan added: “One of the implications is for kids studying – if you want to remember something for long periods you need these connections.

“So it is probably better to study and have good sleep rather than keep studying.”

If you’re worried lack of sleep is affecting your performance at work, studying for exams or at home, you may want to consider complementary therapy. There are a range of treatments designed to help relieve stress and tackle anxiety – common causes of sleep disorders – and help to improve your sleeping patterns. Please see the range of therapies available on our therapy topics page.